Just heard about this and didn't see anything on it so I decided to post it.
PROOF: http://www.treyarch.com/news/434
It is called the "First Strike Map Pack" and will be available on Feb. 1st (Xbox Live only at first)
It will cost 1200 Microsoft points or $15.
It consists of 4 Multiplayer maps and one zombie map.
Multiplayer maps:
-Kowloon: Based off the Kowloon area in SP, it is a "raining rooftop map".
-Berlin Wall: Located in Berlin (obviously) and it is a battle between east and west Berlin.
-Stadium: An athletic complex/hockey rink in the Northeastern US.
-Discovery: An abandoned German research station from WWII.
Zombie map:
-Ascension
EDIT: Apparently, the MP maps will have a greater focus on variety of gameplay, more sniper oppurtunities, more interactibility (supposedly at least one interactible item in each map).
EDIT 2: Updated maps with a brief description.
EDIT 3: Link to thread with early pictures.
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